Electrical apparatus having windings



1. GOODMAN. ELECTRICAL APPARATUS HAVING WINDINGS. APPLICATION F-ILED NOV. 20, 1917.

1,390,77 9, Patented Sept. 13,1921.

' .4. x95 ob y a] d .j

Ireland,residing at Hayes,in the county of Middlesex, England, have invented Improvements inor Relating to Electrical Api s l voltage, internal reflectlon or local resonance, or internal reflections and local 'resO-h To rill uihom it concern umrsn STAT Es 'rosnrrr eoonmnr, or HAYES, ENGLAND.

Beitknown that I, JOSEP J GOODMAN, a subject of the KingofGreatBritainand paratus Having Windings, of which the fol-f lowing is a specification. V a This invention has reference to electrical I; apparatus of various kinds having windings designed to be operated at fixed voltages and also to, apparatus having'windings designed tobeoperated at different times at different voltages. In windings of apparatus of the -first kind,and in part or parts-of windings of apparatus of the second kind that is or are for the time being out of use., electrical stresseslothigh value are liable to be setup through variousfcauses, including local resonance occasioned by electrical disturbances and surges and by internal reflections of such disturbances and surges and which stresses sometimes cause breakdown of the apparatus. e t i bus, in. transformers, which may be taken as an example of apparatus of'the kind referred to, it may occur that owing to the'capacityand inductance values of one of the windings, say for example 'the primary windings,-designed to be, operated at a fixed its breakdown a a fsimilarly, in the case of a winding of a transformer, frequently the primary wind nance, mayarisein such windings and cause ing, designed to beoperated at different times at difierent voltages and wherein for this purpose a part or parts of-such windings is or are arranged to be put out of action, being for this purpose partly or completely disconnected from the circuit,it may happen that when the main portion of the winding is in action, an electro-static stress,

due forvinstance to an electric surge or the:

length of the winding in apparatus of the:

; Application'filed November 20, 1917. Serial No. 202,955;

ELECTRICAL arrms'rns navriwc wrnnmesq first mentioned kind, or,"in apparatusof the secondly mentioned 'kind, between the main portion of the windingthat is in ci'rcuit' and'the part or parts of the winding that is or are disconnected, and also it may PATE T lorries,

V Specification of Letters Patent. ratefitdfiebt 13,

be between each'adj acent pairof such'parts,

where such exist, protective means adapted] to prevent or arrest the passage there through of undue electric stresses and com- I prising for instance one or more inductances,

such for instance as chok ng co1ls, or one or more capacities, such for instance as condensers,j or oneor moreinductan'ces and one or more capacities connected: in parallel orin series, the said protective meansfbeing external tolthe actual winding and connected to tapp'ings'brought' out therefrom orum;

purpose atthe desired points.

, In the first case, in which load has to pass through the protective winding togetherjthe inductance or fe r pacity, or inductance and capacity connected in parallel or serieajshouldb'e of such value 7 as toallow of the normal full load passing the man than] means 'connecting the 'active parts of the throughitjor them but not of excessive loads. Q

It should also be of such ajvaluefthat, .1111" conjunction with the computed "values of'thel inductance and capacity of the; windings,

adjacent to the tapping terminals to which the ldeviceflisconnect emi the possibility of damage to the winding 7 due to; causes such those mentioned, will e rende ed small.

Infthesecond case, the inductanceor capacity, or inductance and, capacity 'connected in paralle'llor s'eries'shouldbe of such value that'in conjunction withthe computed values for the inductance and Capacity of the disconnected part or parts; of the wind;

ing that is or are-ffor the time being inop ative,.the possibility of damage to such disconnected part or parts of thewinding,-due

to causes such as those jmentioned, will be rendered very small, In thiscase, the, protective means although connected to the active portion of thewinding through, a terminal or: tapping connected thereto, will neverthelessbe outside the circuitfof such active portion of the winding and willtherefore normally not be traversed by current,

or only a very small one.

It will be understood that although the inductance or choking coil referred to acts also as a resistance, it may be necessaryincer tain instances to'increase such resistance by the addition of a separate non-inductive-re sistance. Also that where a capacity or condenser is connected in the circuit, a resistance is present in series with the same (due to.

the connections) and it may be necessary in some cases to 1110115386. this resistance by the addition of a non-inductive resistance, of prescribed value.

Whenin protective means of the kind re ferredjto, aninductance and acapacity are connectedfin parallel, an inductance or. a.

resistance may. be. arranged in series with the capacity.

. several 's'ectionsof the fwi'ndingin series. I e 40 .a static transformer. V are diagrams showing modified. cons'truc-' Protective means according .to the .inven tion. can be, applied to the windings of apparatus of various kinds liable to be subjected temporarily. to. dangerous electrical stresses suchasfthose referred to, so that the invention is widely. applicable.

In the accompanying illustrative drawings, Figure 1 shows diagrammatically, the application of the invention to electrical apparatus pf the kindfirst herein referred to andFig. 2 is asim'ilarview showingit appliedwo electrical apparatus of the kind secondly herein referred to, the electrical apparatus in each case being represented as Figs. 3,4, 5 and 6 tions of the protective means.

In F1 1 a, a a are sectionsof the pr1- mary wnidmg of the transformer fromadjace-ntends ofvwhichv extend to the exterior.

of}the,-t ransformer, tappings' b,b 'to terminals c cbetween each, pair of which is connected anfinduct'ance', d, such as a choking coil, the, several choking coils connecting the is. the secondary winding ot the transformer. f' and g" are the current supply leads across which the said sectionsof the primary winding are connected.

' In the se ti l $..0,. the" Primary winding of the transformer f which? only one -1: some m ingluset at any given time according tothe' voltage to be produced in the secondary-winding e.

.. ,In the example, only the section afis connected up to the-mains f andg for. use. In.

this case also,'tappings b, bextend from the adjacent-ends of adjacent sections of the winding to terminals c c between each pair ofwhich an inductance (Z, such as a choking coil, isconnected as shown.

Fig. 3 showsa condenser as the protective meansconnected between adjacent sections of the winding; Fig. 4 shows achoking coil and a condenser connected in parallel betion with a pair of winding sections of electric stress quenching means possessinginductance arranged to alone connect said sections indirect series relationship, there being consequently no circuit between the sections except that due to the said quenching means.

3. In electrical apparatus, the combination with a pair of winding sections of electricstress quenching means comprising an inductance device and a capacity arranged to alone connect the said sections in direct series relationship, there beingconsequently. no'circuit. between the sections except that due to the inductance device andcapacity.

4. In electrical apparatus, the combination with a pair ofwinding sections of electric stress quenching means comprising an inductance device and acapacity connected in parallel with one another and arranged to alone connect the said sections indirect series relationship, there being consequently no circuit between the sections except that due tofthe said inductanceqdevice and capacity. M 1

5. In electrical apparatus-the ,combination with a pair of winding sections 0felec-' tric stress quenching means comprising an inductancede'vice, and, in parallel therewith, a series connected capacity and inductance, the said quenching meansbeing arranged to alone connect the said sectionsiin direct. series relationship, there being consequently no circuit between, the sections exceptithat due to the said quenching means. 7

6. In a static transformer, a winding con: nected at its ends to terminal connections and divided into sections, two tappings; brought out from the ends of .adjacent sec tions and. electric stress quenching; means connected to and between said tappings and alone connecting said sectionsthrough i'said tappings indirect seriesrelationship,there being consequentlyno circuit between the, sectionsez'rcept that. due to. said quenching means. l

7. In" a static transformer, a primary winding connected at its ends to terminal connections and divided into'sections, pairs of tappings brought out fromtheends. ofadjacent sections of the winding, electric stress quenching means connected to and between said'tappings and. alone connecting said sections through said tappings in direct series relationship, there being .tween one end of one of the sections of winding and the adjacent end of the stress quenching means.

Signed in London, England, this 5th day of November, 1917.

JOSEPH GOODMAN Witnesses:

FREDERICK WILLIAM YoUNGH, 'DQRQTHY CONSTANCE BENWELL. 

